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Re: Success with Synchronous rotary gap.





---------- Forwarded message ----------
Date: Wed, 22 Oct 1997 08:09:35 -0400 (EDT)
From: FutureT-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: Re: Success with Synchronous rotary gap.

In a message dated 97-10-20 12:06:52 EDT, you write:
   >snip>
<< the rotor had to be shifted a full 90 degrees (from what we had used on
> Rods coil) and the gap now runs sweetly with a very even 100 Hz buzz.
> Also I now get no arcing across the safety gaps and even the resistors I
> have across the filter chokes run cooler. It seems from all this that
> placing the gap across the trannies might be good for staionary gaps but
> is no good for rotaries.

Hi Peter,

I'm glad to hear you're getting good results using the sync-gap.
They certainly seem to help for neon systems.  I place my sync-
rotary across the tranny output (parallel with safety gap), and 
haven't had a problem.  I don't know why yours worked better
with the cap across the tranny.  Have you tried the parallel set-up
again since re-phasing the gap?  

> Also the peak of the AC cycle is substantially
> phase shifted, possibly because of resonant charging effects. I am now
> getting regular 40" strikes, not a match for John Freau's efforts yet
> but I think some more tuning and playing with coupling might improve on
> that. Also I am only running 11 nF as opposed to 13 (according to the
> formula) so resonant charging is probably not optimum. Anyway, many
> thanks to John Freau's excellent posts on synch rotaries - I'm now a
> great believer in the synch spark gap!

Well, thanks for those nice comments.  The AC phase shifting is 
normal for resonant charging, and is a benefit since it causes the 
gap to fire during a low point on the sine wave of the incoming AC. 
This reduces the transformer losses during the time the tranny is
shorted by the gaps.  

Synching for today and tomorrow,

John Freau
 
> Do many of you guys that run pole pigs use synch gaps, and if
>so were they a big improvement?

> Cheers,
 
> Peter E.
  >>